The overall objective is to progress toward an account of human choice and adjustive behavior in terms of concepts drawn from several theoretical strands: (1) a general theory of reinforcement based on feedback processes and drive-amplifier mechanisms, (2) information-processing models and cognitive theory of memory structures and functions implicated in choice and problem solving, and (3) models of decision processes. Experimental researches are directed toward working out in detail the ways in which cognitive capacities and functions in normal human beings modify motivational mechanisms and the selection and organization of actions. Principal lines of research include (1) elucidating the interaction of memory for frequency of events and categorical memory regarding contingencies and values in verbal discrimination and differential reward learning, (2) investigating the form in which values are represented in both long- and short-term memory and the retrieval and comparison processes that relate these assumptions to performance, (3) analyzing the mechanisms that enable human beings to deal with differential delays and values of events that have never been experienced and the sources of capacity limitations that often result in less than optimal choice behavior. The methods will combine the simulation of various types of choice situations in a computer-controlled environment and the formulation and testing of models capable of predicting and interpreting behavior in these situations.